Dynamics of two colliding Bose condensate in a magnetostatic trap

We experimentally and theoretically investigate the dynamics of two trapped condensates in a magnetostatic trap. The two condensates, being in different internal Zeeman state (/F = 2, m = 2) and /F = 2,m = i]), experience external parabolic potentials that differ by both curvature and equilibrium position. The dynamics of the system, exhibiting large amplitude oscillations of the /F = 2,nt = 1] condensate, is affected in a profound manner by the periodical inter condensates collisions. In particular, we show that both an amplitude damping and a frequency shift occur. Measuring the former allows to study the elastic scattering, whose suppression is a manifestation of the Bose condensates superfluidity, while the latter gives access to the cross scattering length alpha.